From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Page two of a Felixstowe report comparing the performance of aluminium and copper/asbestos washers on engines.
| Identifier | ExFiles\Box 42\4\ Scan034 | |
| Date | 1st April 1933 guessed | |
| -2- Felixstowe Report No. F/Eq/69A. was broken, one broken and corroded, and three corroded. Three of these were fitted in very exposed conditions on air-cooled engines in small float planes. None of the sparking plugs to which the aluminium washers were fitted were protectively coated. All washers were removed and refitted a number of times and appear to have suffered very little damage, particularly those used on the Brooke motor boat which were fitted thirty times. In no instance did the plugs show signs of loosening, and there were no signs of leaking joints. 5. Conclusions. In engines not exposed to very severe conditions the aluminium washers appear to be definitely superior to standard copper and asbestos washers, but in air-cooled engines fitted in small float planes, where the engines are subject to spray when landing and taking off, copper and asbestos washers are better. The life of the aluminium washers would appear to be longer than that of the copper and asbestos washers under normal circumstances. The aluminium washers appear to deteriorate less than copper and asbestos washers when fitted a number of times. --------------- | ||